1. Field of the Invention
The present invention relates to free-standing watercraft lifts and watercraft covers for use with watercraft lifts.
2. Description of the Related Art
The use of boat covers to protect boats is well known. A number of designs are currently known to perform this basic operation. Many boats have multi-section covers, often with one covering the bow section and another covering the aft section. The covers are typically shaped to cover at least portions of the three-dimensional shape of a boat and are manually spread out over the boat and then manually attached using snap or other fasteners. The bow section is attached with fasteners around the perimeter of the bow section especially when there is a bow opening. The aft section is attached to fasteners on the windshield, or in front of the windshield, as well with fasteners around the perimeter of the aft section. This common cover system has several negative aspects for the user. The large number of snaps or other fasteners used make the covers time consuming to install. The covers are often difficult to install after the material ages. The covers are large and awkward to store on-board. The covers can be dirty, and unpleasant to handle. The covers tend to lose shape, causing pockets of water, which further cause a loss of shape and pools of water. The covers do not cover a significant amount of hull surface surrounding the covers, and do not cover significant portions of the sides of the boat with which used, which allows fading in the sun and fails to protect these areas from dirt. The covers provide no security, which makes the contents of the boat and the boat itself vulnerable to theft.
Several two-dimensional automatic cover designs are currently known. U.S. Pat. No. 3,549,198 uses a rotating arm to pull a flat cover over the top of a dump truck to secure the contents. This design would not be ideal for use with a boat lift since the cover is two-dimensional, non-adjustable and would be impractical to fit the three-dimensional shapes of various boat types with which the lift might be used.
It is known to use a two-dimensional cover design similar to that of U.S. Pat. No. 3,549,198 on a portable boat lift for a pontoon boat. However, this design does not provide protection for the sides of the boat. It also is more vulnerable to side wind, since it has exposed edges that catch the wind. The design use a roller fixed to the front, and a set of arms which pull the cover rearward like a window shade. This type of design is undesirable for application on a boat, since pulling the cover rearward from a fixed roller at the front of the boat lift would cause the cover to slide over and drag on parts of the boat, causing cover wear, and potential boat damage. The fixed cover in the front also blocks views and is not attractive since the roller remains visible at the front even when the cover is deployed. Further, the lift of U.S. Pat. No. 3,549,198 does not provide any protection against operation of the lift when the cover is deployed, which can cause cover and/or boat damage, especially if installed on lifts that translate rearward when lowering, such as the lift of U.S. Pat. No. 5,908,264. Since the lift of U.S. Pat. No. 3,549,198 is not remote controlled, another drawback results from the user being required to operate it from the location of a control box. This does not permit manually adjusting the cover when operating in situations where it is not seating correctly.
U.S. Pat. Nos. 4,019,212 and 6,786,171 describe a cover system that does not touch the boat. These systems have a fixed roof with structure and retractable sides that completely surround the boat. The tall sides of these systems block views and are more vulnerable to wind. For use on a free-standing boat lift, the fixed roof structure can make the lift vulnerable to tipping. Because of the fixed roof, these systems often require permitting and are highly regulated.
U.S. Pat. No. 4,019,212 is a device that attaches to a free-standing boat lift and lifts the cover off vertically. This design requires an external frame and overhead structure to lift the frame. The design is not conducive to cover the full sides of the boat. Since the cover creates a shadow over the water even when the boat is off the lift, this design would often be regulated as a canopy or covered moorage rather than as a boat cover.